Alarm switch



P- 1931- c. o. PETERSON ALARM SWITCH Filed Jan. 21, 1930 Inventor 6'42? 6 ffanso A iiorncg,

Patented Sept. 1, 1931 UNITED STATES CARL O. PETERSON, OF ESSEX, IOWA ALARM SWITCH Application filed January 21, 1930. Serial No. 422,361.

This invention relates to an improved electrical circuit switch especially adapted for use in automatically controlling an alarm, for instance, a fire alarm.

More specifically stated, the invention has particular reference to a normally open switch, and an inflammable and fusible means for holding the movable elements of the switch in normally open position.

In carrying the invention into effect I have found it expedient to accomplish this result by utilizing a box having a spring pressed switch blade arranged therein and held in open position by a fusible transparent cover.

My principal aim is to generally improve upon appliances of this class by providing one which is characterized by comparative simplicity, durability, practicability, and

other features which will fulfil the requirements of an invention of this class in a high.- ly satisfactory manner.

In the drawings Figure 1 is an elevational view of a device constructed in accordance with the pres ent invention.

Figure 2 is a front or face view thereof.

Figure 3 is a cross sectional view showing the switch construction.

As seen in Figures 1 and 3 the reference character 4 designates a box or casing of appropriatematerial and on the open side of this and around the margin I provide an inturncd retaining flange 5. Inside of the box is ablock mounting 6 carrying a standard 7 on which the blade 8 of the switch is pivotally mounted. The blade is shaped somewhat like a bell crank and includes a blade portion 9 for cooperation with the relatively stationary contact element 10. In addition it includes a handle portion 11 with which one end of spring 12 is connected. The spring is anchored in the box as seen in Figure 1 and serves to press the handle portion of the switch blade 8 outwardly in a manner to force the blade 9 into engagement with the contactelement 10. The switch is maintained in open position, however, through the presence of the fusible inflammable laminated cover generally designated by the reference character 12. This comprises sheet material, the inner sheet or lamination being designated by the numeral 13 and being fastened throughout its marginal portion, as at 14, to the corresponding portion of theouter or top sheet or lamination 15. The free marginal portions of the laminations 13 and 15 embrace the flange 5 therebetween as indicated at 16, thus holding the cover in place. The marginal edge of the outer sheet or lamination 15 is provided with a multiplicity of points, tongues or extensions 17 which project outwardly beyond the box and which serve to become ignited easily and readily in case of fire.

\Vhen the cover 12 is in the position seen in Figure 8 it presses against the handle portion 11 of the switch blade 8 thus holding the blade portion 9 disengaged from the contact element 10. As soon, however, as the cover is destroyed by flames from a fire or melted from heat, the spring comes into play and forces the blade 9 into engagement with the contact 10 and closes the circuit. The circuit wires are designated by the numerals 18 and 19, respectively, and these are included in an alarm circuit, (not shown).

It is thought that persons skilled in the art to which the invention relates will be able to obtain a clear understanding of the invention after considering the description in connection with the drawings. Therefore, a more lengthy description is regarded as unnecessary.

Minor changes in shape, size and rearrangement of details coming within the field of invention claimed may be resorted to in actual practice if desired.

Having thus described my invention, what I claim as new is 1. A circuit closer of the character described comprising a box having an open side. an inturned flange on said open side of the box, a switch mounted in the box, resilient means yieldingly urging the switch toward circuit closing position, and a fusible closure mounted in the open side of the box and engaged with the switch in a manner to retain said switch open position, said cover comprising inner and outer laminations secured together adjacent their marginal edges, the tree marginal portions of the laminations embracing the flange therebetween in a man ner to retain the closure in position on the box.

2. A circuit closer of the character described comprising a box having an open side, an inturned flange on said open side of the box, a switch mounted in the box, resilient means yieldingly urging the switch toward circuit closing position, and a fusible closure nounted in the open side of the box and engaged with the switch in a manner to retain said switch open position, said cover comprising inner and outer laminations secured together adjacent their marginal edges, the free marginal portions of the laminations embracing the flange therebetween in a manner to retain the closure in position on the box, and integral tongues projecting from the marginal edges of the outer lamination.

In testimony whereof I aflix my signature.

CARL O. PETERSON. 

